1. Field of the Invention
The present invention relates to an information processing system, an image forming apparatus, a control method, and a recording medium.
2. Description of the Related Art
As modes for conducting various types of processing on a server computer side, technologies such as cloud computing systems and SaaS (Software as a Service) have been proposed. With cloud computing, it is possible to simultaneously process requests from many clients by utilizing many computing resources, and performing data conversion and data processing in a dispersed manner. By fully utilizing the characteristics of cloud computing, systems have been proposed in which numerous jobs are scalably processed by implementing a series of processing steps on a server with interlinkage of precisely prescribed tasks, and by simultaneously processing these in parallel. Such a system is hereinafter referred to as a “cloud system.”
In a cloud system, in order to enhance scalability of computer resources and prevent system down-time when requests from clients peak, there is a mode in which a task execution processing unit non-synchronously acquires tasks contained in a job, and executes job processing (title: Windows Azure Queue, Queue Storage Programming, URL: http://go.microsoft.com/?linkid=9734588, issue date: December 2008).
A task execution processing unit is described with a back-end unit as follows. In cases where an anomaly occurs in a back-end unit during task execution processing and where prolonged job processing does not terminate, in order to execute the job processing again, it is necessary to have a retry function which is executed by a back-end unit that is separate from the back-end unit in which the anomaly occurred. Anomalies in task execution processing arise when hardware malfunctions occur in the computer that is running the task, or due to task software bugs and the like. With respect to cloud systems, a method has been proposed in which retry is executed with a separate back-end unit when job execution has been ongoing for a fixed period of time.
However, in a conventional cloud system, the following case may occur as a result of the retry function when job processing is transferred to another back-end unit. In a conventional cloud system, even if the back-end unit in which an anomaly has occurred during execution of job processing transfers the job processing to another back-end unit, its own job processing continues to be executed. Therefore, the back-end unit in which the anomaly has occurred cannot process the next job until the job in the process of execution terminates. As a result, the system as a whole wastefully expends computer resources.
In the case of processing in which job content affects an external system, the external system is doubly affected by the back-end unit already in the process of executing job processing and the back-end unit to which the job processing has been newly transferred, producing systemic inconsistencies. For example, there is processing in which an external system is affected by a job that saves data in the external system or a job that sends a message to the external system.